As the packaging of electronic apparatus continues to downsize a number of factors are affecting the ability to position integrated chip packages on circuit cards, to dissipate the heat produced by the integrated circuit chip or chips in the package and to structurally support heat dissipation apparatus so as to prevent excessive forces from being applied to the chip package.
A trend is developing in the art to employ heavy finned heat sinks the size of the chip package that are removably attached with spring pressure to chip package socket members. Such structures are illustrated in U.S. Pat. Nos. 5,329,426; 5,307,239; 5,276,585 and 5,208,731.
As the art is progressing the integrated circuit package is being constructed as a high density double faced package unit with closely spaced electrical contacts on one face that is positioned in contact with the wiring on a supporting member such as a circuit card and with the other face of the chip package that is to be away from the circuit card available for heat transfer.
It is becoming essential in the packaging of modern high speed electronic apparatus that there be the capability of mounting the chip packages on the circuit cards very close together with accommodation for other components being on the circuit cards adjacent to the chip packages; that heat dissipating apparatus, such as a finned heat sink member, may have an area larger than the chip package area; that the heat sink may be compressed against the chip package permitting accommodation of differences in expansion while not transferring forces supporting the heat sink to the chip package; and that the heat sink be removable independent of the chip for repair and chip repopulating of the electronic apparatus.